1. Field of the Invention
The present invention relates to inflatable bolsters used in vehicles. More specifically, the present invention relates to an inflatable bolster system for restraining a vehicle occupant during a collision.
2. Description of Related Art
Inflatable airbags enjoy widespread acceptance as passive passenger restraints for use in motor vehicles. This acceptance has come as airbags have built a reputation of preventing death and injury over years of use. Studies show that in some instances, the use of frontally-placed vehicular airbags can reduce the number of fatalities in head-on collisions by 25% among drivers using seat belts and by more than 30% among unbelted drivers. Other statistics suggest that in a frontal collision, the combination of a seat belt and an airbag can reduce the incidence of serious chest injuries by 65% and the incidence of serious head injuries by up to 75%. These numbers and the thousands of prevented injuries they represent demonstrate the life-saving potential of airbags and the need to encourage their use, production, and development.
Airbags are generally linked to a control system within the vehicle that triggers their initiation when a collision occurs. Generally, an accelerometer within the vehicle measures the abnormal deceleration caused by the collision event and triggers the ignition of an airbag inflator. This control system is often referred to as an electronic control unit (or “ECU”). The ECU includes a sensor that continuously monitors the acceleration and deceleration of the vehicle and sends this information to a processor which uses an algorithm to determine whether a deceleration experienced by the vehicle is a collision or not. Additional sensors may be linked to the ECU to allow the proper detection of side-impact collisions, rollovers, etc.
When the processor of the ECU determines, based on a set of pre-determined criteria, that the vehicle is experiencing a collision, the ECU transmits an electrical current to an initiator assembly connected to an inflator that is coupled to the airbag module. The initiator activates the inflator. An inflator is a gas generator that typically uses a compressed or liquefied gas or mixture of gases, a solid fuel, or some combination of the above to rapidly generate a volume of inflation gas. The gas inflates the airbag, which deploys into the path of the vehicle occupant and absorbs the impact of the vehicle occupant.
As experience with the manufacture and use of airbags has progressed, the engineering challenges involved in their design, construction, and use have become better understood. First, most airbag systems are designed to rapidly inflate and provide a cushion in front of or near an occupant based on a presumption that the occupant will be in a predetermined position. Problems have been noted to occur when the occupant is “out of position” with regard to this presumed placement. Similarly, problems may occur when the occupant, though possibly at first in the predicted position, strikes a glancing blow to the airbag, and is then deflected off of the airbag before proper deceleration can occur.
Out of position injuries may be attributed in part to the fact that most airbag systems have been primarily designed for deployment in front of the torso of an occupant. More specifically, such airbags are disposed for deployment between the upper torso of an occupant and the windshield and instrument panel. During a front-end collision, there is a tendency for an occupant, particularly one who is not properly restrained by a seat belt, to slide forward across the seat. In some cases, the vehicle occupant may “submarine,” or slide off of the front of the seat and under the primary frontal airbag during impact. This may compromise the ability of the primary airbag to provide proper protection to the occupant.
In order to avoid danger of injury to occupants as a result of such poor positioning, knee bolster airbag systems have been developed. These airbags deploy during a collision event and engage an occupant's knees or lower legs. This holds the occupant in place on the seat, and improves the kinematics of the occupant.
Such knee bolster airbag systems, like many other airbag systems, often suffer from high cost and from engineering problems. Specifically, knee bolster airbags are difficult to design to be mounted in the tight spaces available under the steering column or dashboard in order to be properly positioned to contact a vehicle occupant's knees. Additionally, the airbags themselves must be treated with various coatings to protect the fabric of the airbag from the heat of the gas. Finally, in some specific applications, fabric airbags have proven very difficult to install.
In other types of collisions, airbags are positioned at the side of a vehicle occupant to cushion impacts with a lateral surface such as a door or other interior panel. These generally take the form of side-curtain airbags and side-positioned airbags designed to protect the head, torso, pelvis, or any combination of these and other body regions. These airbags must be designed to provide adequate support under high load conditions. Further, such airbags pose design difficulties because of the need to mount them such that they can easily deploy into the often narrow space between a vehicle occupant and the door or side panel of a vehicle.
Thus, it would be an advancement in the art to provide an inflatable bolster system to protect a vehicle occupant during collision events in a wide variety of situations. Specifically, it would be an advancement in the art to provide an inflatable bolster suitable for mounting in a vehicle under the steering column or dashboard; or in a door, side panel, or trim panel. It would also be an advancement in the art to provide an inflatable bolster including both metal and non-metal components. Additionally, it would be an advancement in the art to provide an airbag system using heat-damage-resistant components to allow the use of lower-cost pyrotechnic inflators. It would also be an advancement in the art to provide an inflatable bolster device using fewer components than the bolsters currently available. It would be a further advancement in the art to provide an inflatable bolster in which the bolster portion of may be configured to function as a decorative trim panel for the interior of a vehicle.
Such a device is disclosed and claimed herein.